1 files changed, 33 insertions, 0 deletions
diff --git a/devtools/client/debugger/src/actions/utils/middleware/context.js b/devtools/client/debugger/src/actions/utils/middleware/context.js
new file mode 100644
index 0000000000..ebadaa4eff
--- /dev/null
+++ b/devtools/client/debugger/src/actions/utils/middleware/context.js
@@ -0,0 +1,33 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at <http://mozilla.org/MPL/2.0/>. */
+
+import {
+  validateNavigateContext,
+  validateContext,
+} from "../../../utils/context";
+
+function validateActionContext(getState, action) {
+  if (action.type == "COMMAND" && action.status == "done") {
+    // The thread will have resumed execution since the action was initiated,
+    // so just make sure we haven't navigated.
+    validateNavigateContext(getState(), action.cx);
+    return;
+  }
+
+  // Validate using all available information in the context.
+  validateContext(getState(), action.cx);
+}
+
+// Middleware which looks for actions that have a cx property and ignores
+// them if the context is no longer valid.
+function context({ dispatch, getState }) {
+  return next => action => {
+    if ("cx" in action) {
+      validateActionContext(getState, action);
+    }
+    return next(action);
+  };
+}
+
+export { context };